1. Technical Field
The present invention relates to a substrate transfer apparatus which transfers substrates between substrate storage cases, to a method of transferring a substrate, and to a method of manufacturing an electro-optical device using the method of transferring a substrate.
2. Related Art
In general, a liquid crystal display device is manufactured such that a plurality of liquid crystal display devices are formed on a pair of glass substrates to cut out a single liquid crystal display device (hereinafter, referred to as a single product) from the glass substrates. The glass substrate, which is used in such a manufacturing method, has sides each having a length of several hundreds of millimeters or more.
On the other hand, the liquid crystal display device may be manufactured by bonding a plurality of counter glass substrates, each of which has a diagonal size of about two inches or less corresponding to the single product, to a large glass substrate in advance, and cutting out a single liquid crystal display device. This manufacturing method is performed in order to avoid a risk of miscombination at the time of bonding the counter glass substrates or to control a gap between the glass substrates with high precision. In this case, a method of manufacturing a liquid crystal display device has a process of transporting the counter glass substrates each having a size corresponding to the single product. As an example of such a process, a process of drawing out the counter glass substrates stored upright in a substrate storage case one by one and transferring the counter glass substrates to a different palette-shaped substrate storage case side by side can be exemplified.
However, an apparatus for transferring a small counter glass substrate, which can be applied to the above-described process, had not been suggested yet. At present, the counter glass substrates are transferred by human hands. There is a possibility for problems to occur when transferred by human hands, such as the substrate may be damaged, a transfer position may be misaligned, yield is lowered due to an error in a storage direction of the substrate or the like, the number of workers needed is increased, or it takes too much time for a worker to become proficient.